The present invention relates to a universal joint that allows a driving member to rotate a driven member. More specifically, the invention relates to a spider for use in a universal joint.
Universal joints provide a mechanism for attaching two shafts having coplanar axes. One shaft functions as a driving member, and the other shaft functions as a driven member. The connection made by the universal joint allows the driving member to rotate the driven member, thereby transferring rotational movement between coplanar shafts.
A typical universal joint connection includes a central portion, commonly referred to as a spider. The spider has four outwardly extending legs, or trunnions. A bearing cup is secured to each of the trunnions. A yoke having two opposed arms is connected to the end of each shaft. Each arm of the yoke is attached to a bearing cup. Each yoke is attached to bearing cups on opposing trunnions.
Frequently, each trunnion defines a recess for storing a lubricant. The recess allows the lubricant to reach the bearing cup and other parts of the joint during use, which promotes longer life of the universal joint. The recess is typically a central void in the face of the trunnion. No material is present in the recess. As a consequence, this structure prevents the use of methods of attaching the bearing cup to the trunnion that require a resistance or support surface in the position occupied by the recess. An example of such a method is a staking operation.
The present invention provides a spider for a universal joint that includes a support surface within the lubrication recess of the trunnion. The support surface allows a bearing cup to be staked onto the trunnion. In a preferred embodiment, the invention comprises a spider including a main body and four trunnions extending outward from the main body. Each trunnion has a first end adjacent the main body and a second end opposite the first end. A recess is located in each trunnion, extending from the second end toward the first end. A support surface is disposed within the recess of each trunnion.